/Engine/Source/Editor/CurveEditor/Public/Tree/CurveEditorTreeFilter.h
Base class for all filters that can be applied to a curve editor tree. Filters are identifyable through their type (seeGetType()), which is a pre-registered static value retrieved throughRegisterFilterType(). Client types can inspect this for supported types, and static_cast<> for implementation details. Filters also contain a pass, which is used to separate filters into separate passes. Filters applied within the same pass are matched as a boolean OR, filters in different passes are matched as a boolean AND.
struct FCurveEditorTreeFilter
bool:  1
bExpandToMatchedItems
Determines if tree paths should be expanded down to matched items
int32
FilterPass
Defines which pass this filter should be applied in
ECurveEditorTre...
FilterType
The static type of this filter as retrieved by RegisterFilterType